New Zealand is on its way to being invasive species-free, using a combination of traditional and high-tech eradication methods.
The battle started in the 1960s, when residents of an island off New Zealand eradicated rats from the island. Now New Zealand citizens are going after brushtail possums and stoats, along with three species of rat that have invaded the country. The eradication order is a tall one: to be free of invasive predators by 2050.
To do that, officials and citizens are combining state-of-the-art trapping devices with older traps and poison baits. As invasive mammalian residents are eliminated, officials keep a close watch on ferry docks and other points where new hitchhikers can come in.
Some of the air-spread poisons, such as 1080, are used only in areas that have no other wildlife, since the poisons kill non-target animals and are opposed by hunters and animal rights groups. Other mechanisms, such as a trap created by Goodnature, make effective killing machines and require little human intervention. The Goodnature trap can reset itself and uses wireless electronic biosensors that detect species-specific molecules given off by animals.
Some of the ideas still in the works involve drone-emitted poisons and Trojan Female rats that would breed sterile males. New Zealanders are skeptical about genetically bioengineered species, so scientists are skeptical about the reception to a GM rat. In addition, they are unsure about how long eradication would take if productive females continue being born.
One of the challenges to most eradication efforts is getting residents involved, but specialists say that it’s not much of an issue in New Zealand. Thousands of volunteer community groups spend their time setting and checking traps. One suburb has already eradicated predators after neighborhood groups set traps in their backyards.
In addition, the government and philanthropic groups have said they will donate about 3 billion New Zealand dollars toward eradication. Experts have estimated that $9 billion may be needed but hope that technological advances will reduce the cost.
Source: Owens, Brian (2017). The Big Cull: Can New Zealand Pull Off an Audacious Plan to Get Rid of Invasive Predators by 2050?” Nature, vol. 541, http://www.nature.com/polopoly_fs/1.21272!/menu/main/topColumns/topLeftColumn/pdf/458148a.pdf